In a number of industrial applications, liquid suspensions or slurries may be fed to screening equipment to separate out solids of various sizes from the liquid or slurry. Often, it is desired to discharge the slurry at several locations along a vibrating screen or on more than one screen or both. For example, embodiments of the stacked and staggered screening machine in U.S. Pat. No. 6,431,366 include multiple screening units on a single screening machine. Slurry may be divided amongst each of the multiple screening units for increased efficiency.
Generally, flow dividers are employed to divide the flow of the slurry into multiple flows and/or screening locations. Flow dividers are usually circular tanks wherein the liquid or slurry is introduced tangentially in the upper portion of the tank and undergoes a cyclonic mixing as it descends along the circular wall of the tank. Usually, multiple discharge passages are disposed in common horizontal plane near the bottom of the tank or at least below the tangential inlet passage. Circular flow dividers may further include an annular flange or ledge to increase mixing of the slurry prior to discharge through one of the discharge passages.
Circular flow dividers are generally connected to screening units via hoses. The hoses may be connected to the flow dividers in a circular pattern at each of the discharge passages of the divider. Because the discharge passages are arranged in a circular pattern, either from a bottom surface or horizontal side surface of the flow divider, the discharge passages cannot line up directly above feed boxes of each of the screening units. Instead, hoses are typically curved and/or bent to create a connection to the feed boxes of the screen units. As a result, the hoses are usually different lengths and include bends and/or curvatures to create connections between the discharge passages and the feed boxes.
The circular pattern of the discharge passages, varying hose lengths and constricting bends and curves may lead to siphoning, and circular dividers often exhibit unequal slurry flow distribution. Moreover, because the discharge passages are connected via hoses that bend and curve to provide a flow path to the feed boxes, circular flow dividers typically require substantial installation heights above screening machines to ensure the hoses are not overly curved or bent. Typically, circular flow dividers must be located on a structure that is a floor or more above the screening machine to provide optimal flow characteristics.
Accordingly, there is need for new flow dividers and methods of dividing slurry that eliminate the problems associated with current systems, including eliminating uneven slurry distribution between screening surfaces, eliminating the large space requirements associated with locating a flow divider at substantial heights above a screening unit and eliminating the need for lengthy and/or multiple curved and/or bent hose connections between a flow divider and a screening unit.